This seems to be the best solution. It lets you select country and it even has all the local apps indexed.
Searching by language was locked behind a subscription which infuriated me but I guess subscribing to a service so that you can know what service you should subscribe to seems about right for 2024.
Click the three lines and click settings. Then you can choose a default country. First time using this tool so can't advocate for it but you can absolutely change countries very easily.
JustWatch does a decent job of telling you if a specific movie is on any of the streaming services. For example, I just searched for the movie Tombstone and apparently it's on Apple TV+, Hulu, and AMC's service.
It's not always accurate, so take everything it says with a grain of salt, but it's better than nothing.
I use it very regularly and find it to be completely reliable if you use the web version. If you use the app version, it will leave a lot of options out.
Just search "Where to stream 'show' in 'country'" there are a lot of sites out there that catalog which services have which media and usually include a record of where you've been able to find them historically and when, if it's been announced, a streaming service will lose that media.
Thats what I do when I know what I want to watch but I don't always know what I want, especially when trying to agree with a bunch of other people with different taste.
If you don't know what specific shows you want to watch, you could try going to the streaming services' website. Hidden away at the bottom of the page will probably be an About or FAQ that might let you take a peek at some titles.
I think by design the only way to see the full catalogue is to subscribe. Lots of them have free trials, but it's still a pretty lame way to do business.
If the streaming services are opaque, don't watch anything on them! DVDs from the library, or YouTube or whatever, those are transparent. Not to praise YT, because it has other issues.
This is a very interesting question because it ignores the way that I wander into subscribing at all
I know of some show I want to watch and then after I already know about the show then I seek out the provider for it. After I subscribe and watch the show until I am satisfied with it only then do I bother looking at other shows available on that same provider.
I usually end up watching one or more shows I never would have known about or watched without subscribing for the original show. Eventually I cancel the subscription because there is no interesting shows left.